linux: realtime patch breaks sparc v8, so change it to a conditional patch again

target/linux/config/Config.in.kernel

@@ -111,6 +111,9 @@ config ADK_KERNEL_KERNEL_MODE_NEON
 	bool
 	default y if ADK_TARGET_ARCH_ARM_WITH_NEON
 
+config ADK_KERNEL_PATCH_REALTIME
+	bool
+	
 choice
 prompt "preemptive mode"
 
@@ -134,6 +137,7 @@ config ADK_KERNEL_PREEMPT__LL
 config ADK_KERNEL_PREEMPT_RTB
 	bool "Preemptible Kernel (Basic RealTime)"
 	select ADK_KERNEL_HIGH_RES_TIMERS
+	select ADK_KERNEL_PATCH_REALTIME
 	depends on ADK_TARGET_KERNEL_VERSION_4_1 \
 		|| ADK_TARGET_KERNEL_VERSION_4_4
         help
@@ -142,6 +146,7 @@ config ADK_KERNEL_PREEMPT_RTB
 config ADK_KERNEL_PREEMPT_RT_FULL
 	bool "Fully Preemptible Kernel (RealTime)"
 	select ADK_KERNEL_HIGH_RES_TIMERS
+	select ADK_KERNEL_PATCH_REALTIME
 	depends on ADK_TARGET_KERNEL_VERSION_4_1 \
 		|| ADK_TARGET_KERNEL_VERSION_4_4
         help

toolchain/kernel-headers/Makefile

@@ -28,6 +28,11 @@ ifneq ($(ADK_DISABLE_KERNEL_PATCHES),y)
 	$(TRACE) kernel-patch
 	$(PATCH) $(TOOLCHAIN_BUILD_DIR)/w-$(PKG_NAME)-$(PKG_VERSION)-$(PKG_RELEASE)/linux-$(KERNEL_FILE_VER) \
 		$(ADK_TOPDIR)/target/linux/patches/$(KERNEL_FILE_VER) *.patch $(MAKE_TRACE)
+ifeq ($(ADK_KERNEL_PATCH_REALTIME),y)
+	$(TRACE) linux-rt-kernel-patch
+	$(PATCH) $(TOOLCHAIN_BUILD_DIR)/w-$(PKG_NAME)-$(PKG_VERSION)-$(PKG_RELEASE)/linux-$(KERNEL_FILE_VER) \
+		$(ADK_TOPDIR)/target/linux/patches/$(KERNEL_FILE_VER) patch-realtime $(MAKE_TRACE)
+endif
 endif
 ifneq ($(ADK_DISABLE_TARGET_KERNEL_PATCHES),y)
 	$(TRACE) kernel-target-patch